A small cloth used for the wiping of smelly asses.
a) A host place for the abundant growth of asses.
b) A cut of leather or another select material designed for the covering of unaesthetically pleasing asses.

I hope that when you die, your corpse will provide for a lush and thriving asspatch.

When You are watching pornography, when the Male is "inside" of the female (or other male) While On his back, The small area of this butt that you can see underneath the ballsack is called the ass patch.

Dude Number 1 : Dude ! did you see that porn where the guy is doing that chick while on his back !?

Dude number 2 : Hell yeah I did ! He was SO showing off his ass patch.